// Copyright David Abrahams 2002. | |
// Distributed under the Boost Software License, Version 1.0. (See | |
// accompanying file LICENSE_1_0.txt or copy at | |
// http://www.boost.org/LICENSE_1_0.txt) | |
#ifndef DATA_MEMBERS_DWA2002328_HPP | |
# define DATA_MEMBERS_DWA2002328_HPP | |
# include <boost/python/detail/prefix.hpp> | |
# include <boost/python/handle.hpp> | |
# include <boost/python/return_value_policy.hpp> | |
# include <boost/python/return_by_value.hpp> | |
# include <boost/python/return_internal_reference.hpp> | |
# include <boost/python/make_function.hpp> | |
# include <boost/python/converter/builtin_converters.hpp> | |
# include <boost/python/detail/indirect_traits.hpp> | |
# include <boost/python/detail/not_specified.hpp> | |
# include <boost/python/detail/value_arg.hpp> | |
# include <boost/type_traits/add_const.hpp> | |
# include <boost/type_traits/add_reference.hpp> | |
# include <boost/type_traits/is_member_pointer.hpp> | |
# if BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003)) | |
# include <boost/type_traits/remove_cv.hpp> | |
# endif | |
# include <boost/mpl/eval_if.hpp> | |
# include <boost/mpl/if.hpp> | |
# include <boost/mpl/vector/vector10.hpp> | |
# include <boost/detail/workaround.hpp> | |
namespace boost { namespace python { | |
// | |
// This file defines the make_getter and make_setter function | |
// families, which are responsible for turning pointers, references, | |
// and pointers-to-data-members into callable Python objects which | |
// can be used for attribute access on wrapped classes. | |
// | |
namespace detail | |
{ | |
// A small function object which handles the getting and setting of | |
// data members. | |
template <class Data, class Class> | |
struct member | |
{ | |
public: | |
member(Data Class::*which) : m_which(which) {} | |
Data& operator()(Class& c) const | |
{ | |
return c.*m_which; | |
} | |
void operator()(Class& c, typename value_arg<Data>::type d) const | |
{ | |
c.*m_which = d; | |
} | |
private: | |
Data Class::*m_which; | |
}; | |
// A small function object which handles the getting and setting of | |
// non-member objects. | |
template <class Data> | |
struct datum | |
{ | |
public: | |
datum(Data *which) : m_which(which) {} | |
Data& operator()() const | |
{ | |
return *m_which; | |
} | |
void operator()(typename value_arg<Data>::type d) const | |
{ | |
*m_which = d; | |
} | |
private: | |
Data *m_which; | |
}; | |
// | |
// Helper metafunction for determining the default CallPolicy to use | |
// for attribute access. If T is a [reference to a] class type X | |
// whose conversion to python would normally produce a new copy of X | |
// in a wrapped X class instance (as opposed to types such as | |
// std::string, which are converted to native Python types, and | |
// smart pointer types which produce a wrapped class instance of the | |
// pointee type), to-python conversions will attempt to produce an | |
// object which refers to the original C++ object, rather than a | |
// copy. See default_member_getter_policy for rationale. | |
// | |
template <class T> | |
struct default_getter_by_ref | |
: mpl::and_< | |
mpl::bool_< | |
to_python_value< | |
typename value_arg<T>::type | |
>::uses_registry | |
> | |
, indirect_traits::is_reference_to_class< | |
typename value_arg<T>::type | |
> | |
> | |
{ | |
}; | |
// Metafunction computing the default CallPolicy to use for reading | |
// data members | |
// | |
// If it's a regular class type (not an object manager or other | |
// type for which we have to_python specializations, use | |
// return_internal_reference so that we can do things like | |
// x.y.z = 1 | |
// and get the right result. | |
template <class T> | |
struct default_member_getter_policy | |
: mpl::if_< | |
default_getter_by_ref<T> | |
, return_internal_reference<> | |
, return_value_policy<return_by_value> | |
> | |
{}; | |
// Metafunction computing the default CallPolicy to use for reading | |
// non-member data. | |
template <class T> | |
struct default_datum_getter_policy | |
: mpl::if_< | |
default_getter_by_ref<T> | |
, return_value_policy<reference_existing_object> | |
, return_value_policy<return_by_value> | |
> | |
{}; | |
// | |
// make_getter helper function family -- These helpers to | |
// boost::python::make_getter are used to dispatch behavior. The | |
// third argument is a workaround for a CWPro8 partial ordering bug | |
// with pointers to data members. It should be convertible to | |
// mpl::true_ iff the first argument is a pointer-to-member, and | |
// mpl::false_ otherwise. The fourth argument is for compilers | |
// which don't support partial ordering at all and should always be | |
// passed 0L. | |
// | |
#if BOOST_WORKAROUND(__EDG_VERSION__, <= 238) | |
template <class D, class P> | |
inline object make_getter(D& d, P& p, mpl::false_, ...); | |
#endif | |
// Handle non-member pointers with policies | |
template <class D, class Policies> | |
inline object make_getter(D* d, Policies const& policies, mpl::false_, int) | |
{ | |
return python::make_function( | |
detail::datum<D>(d), policies, mpl::vector1<D&>() | |
); | |
} | |
// Handle non-member pointers without policies | |
template <class D> | |
inline object make_getter(D* d, not_specified, mpl::false_, long) | |
{ | |
typedef typename default_datum_getter_policy<D>::type policies; | |
return detail::make_getter(d, policies(), mpl::false_(), 0); | |
} | |
// Handle pointers-to-members with policies | |
template <class C, class D, class Policies> | |
inline object make_getter(D C::*pm, Policies const& policies, mpl::true_, int) | |
{ | |
#if BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003)) | |
typedef typename remove_cv<C>::type Class; | |
#else | |
typedef C Class; | |
#endif | |
return python::make_function( | |
detail::member<D,Class>(pm) | |
, policies | |
, mpl::vector2<D&,Class&>() | |
); | |
} | |
// Handle pointers-to-members without policies | |
template <class C, class D> | |
inline object make_getter(D C::*pm, not_specified, mpl::true_, long) | |
{ | |
typedef typename default_member_getter_policy<D>::type policies; | |
return detail::make_getter(pm, policies(), mpl::true_(), 0); | |
} | |
// Handle references | |
template <class D, class P> | |
inline object make_getter(D& d, P& p, mpl::false_, ...) | |
{ | |
// Just dispatch to the handler for pointer types. | |
return detail::make_getter(&d, p, mpl::false_(), 0L); | |
} | |
// | |
// make_setter helper function family -- These helpers to | |
// boost::python::make_setter are used to dispatch behavior. The | |
// third argument is for compilers which don't support partial | |
// ordering at all and should always be passed 0. | |
// | |
// Handle non-member pointers | |
template <class D, class Policies> | |
inline object make_setter(D* p, Policies const& policies, mpl::false_, int) | |
{ | |
return python::make_function( | |
detail::datum<D>(p), policies, mpl::vector2<void,D const&>() | |
); | |
} | |
// Handle pointers-to-members | |
template <class C, class D, class Policies> | |
inline object make_setter(D C::*pm, Policies const& policies, mpl::true_, int) | |
{ | |
return python::make_function( | |
detail::member<D,C>(pm) | |
, policies | |
, mpl::vector3<void, C&, D const&>() | |
); | |
} | |
// Handle references | |
template <class D, class Policies> | |
inline object make_setter(D& x, Policies const& policies, mpl::false_, ...) | |
{ | |
return detail::make_setter(&x, policies, mpl::false_(), 0L); | |
} | |
} | |
// | |
// make_getter function family -- build a callable object which | |
// retrieves data through the first argument and is appropriate for | |
// use as the `get' function in Python properties . The second, | |
// policies argument, is optional. We need both D& and D const& | |
// overloads in order be able to handle rvalues. | |
// | |
template <class D, class Policies> | |
inline object make_getter(D& d, Policies const& policies) | |
{ | |
return detail::make_getter(d, policies, is_member_pointer<D>(), 0L); | |
} | |
template <class D, class Policies> | |
inline object make_getter(D const& d, Policies const& policies) | |
{ | |
return detail::make_getter(d, policies, is_member_pointer<D>(), 0L); | |
} | |
template <class D> | |
inline object make_getter(D& x) | |
{ | |
detail::not_specified policy | |
= detail::not_specified(); // suppress a SunPro warning | |
return detail::make_getter(x, policy, is_member_pointer<D>(), 0L); | |
} | |
# if !BOOST_WORKAROUND(__EDG_VERSION__, <= 238) && !BOOST_WORKAROUND(BOOST_MSVC, <= 1300) | |
template <class D> | |
inline object make_getter(D const& d) | |
{ | |
detail::not_specified policy | |
= detail::not_specified(); // Suppress a SunPro warning | |
return detail::make_getter(d, policy, is_member_pointer<D>(), 0L); | |
} | |
# endif | |
// | |
// make_setter function family -- build a callable object which | |
// writes data through the first argument and is appropriate for | |
// use as the `set' function in Python properties . The second, | |
// policies argument, is optional. We need both D& and D const& | |
// overloads in order be able to handle rvalues. | |
// | |
template <class D, class Policies> | |
inline object make_setter(D& x, Policies const& policies) | |
{ | |
return detail::make_setter(x, policies, is_member_pointer<D>(), 0); | |
} | |
template <class D, class Policies> | |
inline object make_setter(D const& x, Policies const& policies) | |
{ | |
return detail::make_setter(x, policies, is_member_pointer<D>(), 0); | |
} | |
template <class D> | |
inline object make_setter(D& x) | |
{ | |
return detail::make_setter(x, default_call_policies(), is_member_pointer<D>(), 0); | |
} | |
# if !(BOOST_WORKAROUND(BOOST_MSVC, <= 1300) || BOOST_WORKAROUND(__EDG_VERSION__, <= 238)) | |
template <class D> | |
inline object make_setter(D const& x) | |
{ | |
return detail::make_setter(x, default_call_policies(), is_member_pointer<D>(), 0); | |
} | |
# endif | |
}} // namespace boost::python | |
#endif // DATA_MEMBERS_DWA2002328_HPP |